1. Field of the Invention
The present invention relates to a method of manufacturing a nonaqueous electrolyte secondary battery and a nonaqueous electrolyte secondary battery.
2. Description of Related Art
Japanese Patent Application Publication No. 2003-151638 (JP 2003-151638 A) discloses a lithium ion secondary battery including an adhesive resin layer through which an electrode (positive electrode or negative electrode) and a separator are adhered to each other, in which the adhesive resin layer has a through-hole.
In JP 2003-151638 A, an adhesive resin solution containing a filler, a binder, and a solvent is adjusted and is applied to the separator. Before the adhesive resin solution is dried, the separator and the electrode are adhered to each other and then are dried. As a result, the separator and the electrode are integrated to obtain an electrode body.
However, it is considered that, in this state, the amount of a binder for adhesion decreases in an adhesive interface due to diffusion of the binder to pores of an electrode mixture layer. The adhesion strength between the electrode and the separator depends on the amount of the binder in the adhesive interface. Therefore, during high-rate cycles where expansion and shrinkage of the electrode are severe, it is expected that an adhesion state between the electrode and the separator is not able to be maintained. When the electrode and the separator are peeled off from each other to form a gap, an electrolytic solution flows to the outside of the electrode body through the gap. As a result, in the electrode body, the distribution of an electrolytic solution and a supporting electrolyte contained in the electrolytic solution is non-uniform, which promotes an increase in resistance caused by high-rate cycles.